implement Meyers diffing algorithm

So we have a slight diffing problem — not only are we fairly slow at updating, reordering nodes is also suboptimal. This means that some reorders can be surprising at the worst case, and in a worst case reorders simply take longer than they should.

In computer science this is known as “diffing”, and is a rather well-studied problem. Probably the best known algo for this is the Mayers Diffing algorithm. It’d be neat if we could make use of this for nanomorph.

references

• https://github.com/yelouafi/petit-dom/blob/master/src/vdom.js
• https://neil.fraser.name/writing/diff/
• http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.4.6927&rep=rep1&type=pdf
• https://www.codeproject.com/Articles/42279/Investigating-Myers-diff-algorithm-Part-of

[tunnckoCore]

Heya! 🎉 Following this long time. And as i once mentioned, i once wanted to rewrite it from scratch - for learning, playing and minimizing the size. So code name was “minmorph” - removed the “./events” list, the remaining is almost the same with few optimizations. Actually not sure why we need to list all the events?

Long story short, back then i tested it against nanomorph’s tests and only 1 tests was failing. Recently was touching it more and following the need for benchmarking, i got the @graforlock repo and put it there so we can benchmark. Also added the nanomorphs tests.

And so, the result is all of the normal tests are passing and only 8 of the “keyed” tests are failing! The benchmark results are phenomenal 😃 I’m going to create a clean repo with everything, plus @graforlock’s code and benchmark. Then i’ll PR the implementation so we can discuss and continue on fixing these 8 tests, because i’m not so familiar with the keyed things 😄

The tests are green (almost)

minmorph benchmark - numbers are the same as the @graforlock’s not finished code, which in turn fails pretty much tests.

Nanomorph benchmark

[yoshuawuyts]

@brucou hey! – I’ve casually started working on a WASM version, but there’s no ETA when this might be done.